First-principles study on electronic properties of stanene/WS2 monolayer

Abstract

We present first-principles calculations to study the stability and electronic properties of stanene on WS2 hybrid structure. It can be seen that the stanene is bound to WS2 substrate with an interlayer distance of about 3.0 Å with a binding energy of −51.8 meV per Sn atom, suggesting a weak interaction between stanene and WS2. The nearly linear band dispersion character of stanene can be preserved with a sizeable band gap in stanene on WS2 hybrid structure due to the difference of onsite energy induced by WS2 substrate, which is more helpful to the on–off current ratio in the logical devices made of stanene/WS2. Moreover, the band gaps, the position of Dirac point with respect to Fermi level, and electron effective mass (EEM) of stanene on WS2 hybrid structure can be tuned by the interlayer distance, external electric field and strains. These results indicate that stanene on WS2 hybrid structure is a promising candidate for stanene-based field-effect transistor (FET) with a finite band gap and high carrier mobility.